Boring tool



Feb. 24, 1942.

:J. H. SMITH BORING TOOL Filed Jan. 19, 1938 ATTORNEYS particularly to 'do with a specific improvement Patented Feb. 24, 1942 I I J. H ugoQSmith,

1 Z'BORING r001.

etroit, Mien, assignor to Wesson-ConipanygDet foit, Mich, a -corporation of I Michigan hp iieeltienljeiiuii 19,1938, SerialN0.185,t42 seems; o1.77 5s) This invention relates to a boring .tool and ':has

lating to theadjustmento'f saidatoolsl .1. i

1 In a reamer or-bor'ingtool ..which'comprise's a shaft having transverse or inclined :openings .for

receiving and holding cutters, it has. beentcommon to provide means for adjustably arranging these cutters in the holders- 'Prior'to 'thepres ent'invention some of these means have consisted of nuts which are set at a predeterminedpoint in a threaded cutter opening so that the square end of thecutter will abut the'nut and be held in this position by a set screw acting on the cutter. These devices have proved unsatisfactory since there is no means for positively moving the cutters in and out and these adjusting screws have been thrown outof adjustment by 'the'chattering or vibration ofithe tool so that the cutter slips on the set screw. v I Another attempt to improve on 'boringtools has been to provide threads on one side of opposed horizontal cutters so that theyma'ybe positioned adjacent screws set in the boring tool andmoved in or out by rotation of the screws,-a locking means being provided for the cutters. This hold I ing and adjusting means hasproved unsatisfactory since it has been found impossible to obtain a rough out without considerable chattering. Still other attempts to solve this problem have consisted in tapping the non-cutting end of the cutter and abutting the outer end of a bolt, held in said tap, against shoulders formed in the cutter opening. This device is subject to the same criticism as the first device above described.

The object of the present invention is to provide a boring tool which, for the first time, successfully solves this cutter adjustment problem. It is the object of thi invention to provide an adjustment arrangement for a cutter whereby the cutter may be positively moved in or out of the boring tool shaft at the will of the operator, but which is not affected by any amount of vi-' bration of the'tool. This positive adjustment, in both directions, of the cutter is extremely important in present day production where precision duplication of parts has become such an im-= portant part of manufacturing. With the present invention the cutter is always solidly backed by the adjustment parts and yet the actual adjustment step may be performed much more quickly and accurately than with any previous device. It is necessary that these cutters have a very close fit with the tool so that they do not slip easily. It has been the practice in the past to move the cutter out of the tool by a screw and to move itin by tapping it withasoft ham- .mer. I have devised a devicewhereby the cutter may be moved in or out with all play in the adjustment eliminated. i Other objects and features of theinvention have to do with themeans' for providinjga se'lflocking adjustment device and other details-of structure as will be brought out in the following specifications and claims. f d v F A modification of the invention is illustrated, for purposes of exemplif catiomin the "accompany'ing drawing, in which'z H Fig. 1 is an assemblyview of a 'boring tool showing cutters in position. V v

Fig. 2 is an endview of the assembly. Fig. 3 is a cross-sectional'view illustrating the details of the device.

Figs. 4, 5, 6 and '7 are'cross sections taken 'on correspondinglines of Fig. l. 7

Referring to the drawing, a cutter shaft for a reamer or boring tool is designated I 0; and a cutter I I is 'slidably positioned in aninc'lined'cut ter opening" I2 formed in the" shaft 10.1 The' 'c'u't *tertopen'ing I2 is enlargedat the top' portion {13 to provide a space fQran ad justment means for the cutter. This openinglt is'providedwith threads :14 which extend to within a short :dis-

tance of the bottom of the enlargement I3. The cutter I I is provided with a threaded tap I5 in its non-cutting end I6.

. The adjustment and retaining means for the cutter II consists of a bolt IT, a nut I8, and a spring I9. The bolt I1 is provided with a thread-.- ed shank portion 20 adapted to thread into the opening I5 behind th springv I9 which isfitted into a small tap 2I in the lower end of the top I5 of the cutter. The head of the bolt I! has a flange 22 larger in diameter than the cutter opening I2 and adapted to be received by the enlargement I3. This flange 22 rests, therefore, on shoulders 23 formed between the opening I2 and the enlargement I3. is threaded into the enlargement to hold the flange and, consequently, the bolt in position.

In Fig. 1, a second cutter .I la is located above I the cutter II and, since this is the same as the cutter I I, it will not be described in detail.

The retaining nut I8' ters.

main in place in the recess provided for them. 1

In mounting a cutter, the spring I9 may be dropped into the recess I5 and the cutter may then be inserted in the opening [2 and the bolt I8 turned until the cutter is in the position desired. At this time the set screw 2'! can be tightened into the recess 26 to lock the cutter H in position.

It will be seen that, during the operation of the cutter, there are two means which hold the adjusting bolt I! in the exact position in which it was placed by the operator. One of these means is the set screw 21, which, while holding the cutter l I, will also hold the bolt H. In addition, the spring [9 by exerting pressure against the lower end of the bolt 11 will prevent the vibration of the boring tool from turning the bolt in either direction. In actual tests it has been found that the present invention has permitted much more delicate adjustments of the cutter than ever before has been possible. One

reason for this is that the bolt l1 remains in the position in which it is turned regardless of the vibration. Because of the design of the bolt l1 and the retaining nut I8, it has been possible to eliminate any play in the adjustment of the cut- With the applicants arrangement it is no longer necessary to tap the cutter back into the tool with a hammer. This is distinctly advantageous since with the new tungsten carbide tools it has been found that even slight shocks on the cutting end have resulted in breakage.

What I claim is: v

1. In a boring tool, a cutter shaft having a cutter opening comprising a cutter recess and an adjoining threaded recess aligned therewith, a cutter slidably disposed in said cutter recess and having a threaded tap in its non-cutting end, an

adjustment bolt having a flange arranged to bear on an annular shoulder in said threaded recess and a threaded shank for cooperating with said tap, and a retaining nut threaded into said threaded recess for holding said flange therein to eliminate any play in the adjustment of the cutter.

2. In a boring tool, a cutter shaft having a cutter opening comprising a cutter recess and an adjoining threaded recess aligned therewith, a cutter slidably disposed in said cutter recess and having a threaded tap in its non-cutting end, an adjustment bolt having a flange arranged to bear on an annular shoulder in said threaded recess and a threaded shank for cooperating with said tap, a retaining nut threaded into said threaded recess for holding said flange therein to eliminate any play in the adjustment of the cutter, andaspring in said tap adapted to bear against said threaded shank.

3. In a boring tool, a cutter shaft having a cutter opening comprising a cutter recess, a cutter slidably disposed in said cutter recess, and manually operable means in said shaft behind, and cooperating with, said cutter for positively moving the same in or out of said cutter recess to set position, and resilient means cooperating with said manually operable means for retaining the same in set position.

4. In a boring tool, a cutter shaft having a cutter opening comprising a cutter recess and an adjoining enlargement aligned therewith, a cutter slidably disposed in said cutter recess, manually operable means retained in said enlargement and cooperating with said cutter for positively moving the same in or out of said cutter recess to a set position, and an expanding spring cooperating with said manually operable means for retaining the same in set position.

5. In a boring tool, a cutter shaft having a cutter opening comprising a cutter recess and an adjoining threaded recess aligned therewith, a cutter slidably disposed in said cutter recess, manually operable means cooperating with said cutter for positively moving the same in or out of said cutter recess to set position, and resilient means acting on said cutter and said manually operable means for maintaining said means in aset relative position.

J. HUGO SMITH. 

